MHT CET20243 May 2024Evening ShiftPhysicsMagnetic Effects of CurrentActual
A thin ring of radius ' R ' carries a uniformly distributed charge. The ring rotates at constant speed ' N ' r.p.s. about its axis perpendicular to the plane. If ' B ' is the magnetic field at the centre, the charge on the ring is ( ₀= permeability of free space)
Options
- A₀ ~N 2 RB
- BRB 2 ₀^ N
- C₀ ~N RB
- D2 R B ₀ ~N
Correct answer
D. 2 R B ₀ ~N
Step-by-step solution
A thin uniformly charged rotating ring acts like a current carrying coil. Magnetic field at the centre of current carrying coil, B= ₀ I 2 R Current is given by, I = qN where N is revolutions per second. array ll & B= ₀ q N 2 R & q= 2 R B ₀ N array ...[From(i)]